Bi-planar process pressure flanges couple process fluids in process installations to process variable transmitters, typically process fluid pressure measurement transmitters. Bi-planar process fluid pressure measurement systems are well known in the art and provide a number of advantages over other configurations. Relatively recently, Rosemount Inc., the Assignee of the current application, developed a standardized co-planar pressure sensor module. The pressure sensor module is co-planar in the sense that it presents two process fluid isolator diaphragms that are substantially in the same plane. Rosemount has also developed bi-planar pressure flanges sold under the trade designation Model 305® which are configured to route process fluids to the co-planar pressure sensor module.
As process applications continue to push for higher and higher operating ranges and present more demanding operating conditions, there is a desire to provide pressure transmitters that are capable of providing longer operating lifetimes at more demanding operating conditions. As such demanding operating conditions reach the design limits of modern process fluid pressure transmitters, there are a number of important considerations. First, undue measurement errors can be introduced by the physical deformation of the materials of the process fluid transmitter. Second, leaks can form. And finally, catastrophic failure can occur when physical forces simply overwhelm individual joints or interfaces.
Providing a bi-planar flange assembly that could allow a co-planar process pressure sensor module to operate at higher temperatures, pressures, and/or radiation levels for longer lifetimes would represent a significant benefit to the process measurement and control industry. In particular, measurement and control of process pressures within nuclear power plants would be greatly enhanced.